Until recent years, most document storage and transmission was in the form of hard copy, such as a printed page of text. To meet the need for multiple copies of such hard copy, copy machines were successfully developed. In the most commercially successful type of copying machine, a light image of a hard copy original to be reproduced is projected onto the sensitized surface of a xerographic plate or belt to form an electrostatic image. Thereafter, the latent image is developed with toner material to form a xerographic powder image corresponding to the latent image on the plate or belt surface. The powder image is then electrostatically transferred to a record material, such as a sheet or web of paper or the like, to which it may be fused by a fusing apparatus whereby the powder image is caused permanently to adhere to the surface of the record material.
Man's inability to keep abreast of the ever increasing volume of information now being generated, the development of data processing equipment, and the desire to transmit information more quickly to remote utilization areas has led to the advance of digital computation, storage, transmission and printing techniques. In the area of digital printing, flying spot scanning systems have been used for communicating video information to a scanned light sensitive medium. In such scanning systems, a light beam produced from a source such as a laser is reflected from a surface of a rotating polygon or multifaced mirror to provide a raster scan across a light sensitive surface. The light beam is modulated in accordance with a binary code which represents image information such as alphanumeric characters or the like, with the binary code being accessed from a magnetic disk or tape, provided directly from the output of a computing device, or provided from a remote document scanning device.
With the increased utilization of digital printing, many environments, such as the business office, are called upon to produce a hard copy output from both a hard copy input and a digitally encoded signal representative of video information. At present, this dual capability requires separate copier and raster scanning apparatus, each with its own light responsive medium and projection optics.